Front and/or rear wheels of automobiles are commonly steered in pairs by a linearly shiftable lateral rod, such as a rack in a rack and pinion steering gear, connected at opposite ends to steering knuckles. In manual rack and pinion steering gears, the rod is shifted mechanically by a pinion meshing with rack teeth on the rod. In typical hydraulic power assisted rack and pinion steering gears, the manual effort of the driver is augmented by the output of a fluid motor connected directly to the rod. In electric power assisted rack and pinion steering gears, the manual effort of the driver is augmented by the output of an electro-mechanical actuator which converts the rotary output of an electric motor into linear movement of the rod. The economies effected by eliminating pumps, valves, hoses and the like, together with the availability of improved controllers and sensors, make electro-mechanical actuators attractive for automotive applications. An electro-mechanical linear actuator according to this invention is particularly suited for automotive steering systems and incorporates novel structural elements which simplify the manufacture of the actuator and thereby contribute to manufacturing economy and to improved durability.